Honeywell 4973 Series User Manual

In addition to the General Requirements outlined above, note the following with regard to insertion-type 
mounting: 

•  Make certain the liquid head is above the cell location during measurement.  A vertical insertion (from 

above) or a horizontal insertion can be used. 

•  Allow at least one-half inch clearance beyond the end of the cell and 1/8 to 3/16 inch radius clearance 

to permit circulation of the solution. 

•  It is usually best to have the solution flow up into the end of the cell since it is less likely to result in 

clogging by solids settling in the cell channels. 

•  To be sure that a representative sample is being measured at all times, the solution must continuously 

move through the cell channels.  In a rapidly moving solution, the assembly may be mounted so that 
the existing circulation forces the solution through the channels.  When measurements are made in 
quiescent solutions, artificial means must be provided to force the solution through the cell.  In some 
cases, this may be accomplished by moving the cell up and down. 

Tighten the cell into a 3/4” NPT threaded opening (do not exceed a tightening torque greater than that 
indicated in Section 3.5) using a Teflon thread compound (preferably Teflon tape). 

In addition to the General Requirements outlined in Section 3.1, note the following with regard to flow-
type mounting:  

•  When mounting the cell in a pipe tee or flow chamber such as shown in Figure 1-3, have the solution 

enter the tee from below and exit to the side or from side and exit top.  Be sure the electrodes are 
always as far as possible below the horizontal pipe run so that they are always covered to insure 
flooding of the cell under all conditions; otherwise, the conductivity reading may indicate a value that 
is lower than expected. 

•  In general, the cell should be mounted so that the sample will flow through the channel toward the 

mounting end of the cell, exiting through the other channel hole or through the outer electrode holes. 
See Figure 1-1. 

•  Locate the cell on the pressure side, not the vacuum side, of pumps.  See Figure 1-2. 
•  Avoid a horizontal cell mounting having the flow channel, see Figure 1-1, opposite to the flow exit of 

the pipe line, especially for the 1 and 10 constant cells.  If necessary, refer to Section 5.5.  

•  The 3/4” tee arrangement, Figure 1-3, assures that the cell is immersed well into the flow stream to 

obtain a representative sample.  The tee is not supplied. 

1.  Tighten the cell into a 3/4” pipe tee (do not exceed a tightening torque greater than that indicated in 

Section 3.5).   

2.  If the flow-cell housing is used, assemble the cell and housing and install it in the process flow line or 

in a bypass line as indicated in Figure 1-2.   

3.  To avoid cracking the 055919 flow chamber, use Teflon tape on cell threads and tighten cell only 

enough to prevent leakage.